The organic chemical hydride process for hydrogenating aromatic compounds such as toluene has recently been developed for the purposes of storing and transporting hydrogen in the form of organic hydrides. According to this process, hydrogen is converted into an organic hydride at the site of hydrogen production, and transported in the form of the organic hydride. The organic hydride is separated into the hydrogen and the aromatic compound at a plant or a hydrogen station located near a city or other user of hydrogen by dehydrogenating the organic hydride. The aromatic compound produced from this dehydrogenation process is transported back to the production site of hydrogen to be hydrogenated by hydrogen once again.
The dehydrogenation reaction that is used for producing hydrogen from an organic hydride in the organic chemical hydride process is an endothermic reaction, and, for instance, about 205 kJ/mol of reaction heat is required to generate hydrogen from methylcyclohexane. The reaction heat required for this dehydrogenation reaction may be obtained from the combustion of fossil fuel, but some proposals have been made to use waste heat as the heat source for the dehydrogenation reaction as a part of the effort to minimize the emission of carbon dioxide.
For instance, in a hybrid type hydrogen production/power generation system which produces hydrogen by the dehydrogenation reaction of an organic hydride in the presence of a dehydrogenation catalyst in a dehydrogenation reaction vessel, and uses the produced hydrogen as fuel for the power generation unit, it is known to use the heat recovered from the high temperature exhaust gas of the power generation unit (typically comprising a gas turbine) for the heat required for the dehydrogenation reaction in the dehydrogenation reaction vessel. (See Patent Document 1)